# CVE-2025-71379: vllm - Regular Expression Denial of Service in Multiple Components

Status: published. Published: 2026-06-20. Updated: 2026-11-08.

vLLM versions >= 0.6.3 and < 0.9.0 contain multiple regular expression denial of service (ReDoS) vulnerabilities. Several regex patterns — in vllm/lora/utils.py, the phi4mini tool parser, and the OpenAI-compatible serving chat endpoint — are susceptible to catastrophic backtracking. An attacker submitting crafted input with nested or repeated structures can trigger severe CPU consumption and performance degradation, resulting in denial of service.

## Remediation

- fix: vllm (PyPI): OSV reports a fixed version 0.9.0. Check the advisory for supported release branches. (source: OSV GHSA-j828-28rj-hfhp) — https://github.com/advisories/GHSA-j828-28rj-hfhp

## Affected products and versions

- vllm / vllm (vllm): ≥ 0.6.3; < 0.9.0 (affected, semver); 0.9.0 (unaffected, semver). Source: CNA: VulnCheck
-  / vllm (vllm): 0.6.3 (affected, PyPI); 0.6.3.post1 (affected, PyPI); 0.6.4 (affected, PyPI); 0.6.4.post1 (affected, PyPI); 0.6.5 (affected, PyPI); 0.6.6 (affected, PyPI); 0.6.6.post1 (affected, PyPI); 0.7.0 (affected, PyPI); 0.7.1 (affected, PyPI); 0.7.2 (affected, PyPI); 0.7.3 (affected, PyPI); 0.8.0 (affected, PyPI); 0.8.1 (affected, PyPI); 0.8.2 (affected, PyPI); 0.8.3 (affected, PyPI); 0.8.4 (affected, PyPI); 0.8.5 (affected, PyPI); 0.8.5.post1 (affected, PyPI); Ecosystem version events: introduced 0.6.3; fixed 0.9.0. Source: OSV GHSA-j828-28rj-hfhp

## Severity and prioritization

- CVSS 4.0: 5.3 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.48% as of 2026-11-08; percentile 41.73%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-1333

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/vllm-project/vllm/security/advisories/GHSA-j828-28rj-hfhp (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/vllm-regular-expression-denial-of-service-in-multiple-components (CNA: VulnCheck; third-party-advisory)

- https://github.com/advisories/GHSA-j828-28rj-hfhp (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-j828-28rj-hfhp (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2025-71379; retrieved 2026-11-08; source updated 2026-11-08

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-j828-28rj-hfhp; retrieved 2026-11-08; source updated 2026-08-07

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-71379; retrieved 2026-11-08; source updated Not reported

Revision: 8d0f1b28cc24bcca879608f3742e565f81410d84116547e68c18e01612128c25

Canonical: https://y2.dev/cve/CVE-2025-71379

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